1. Technical Field
The present application relates to an all-solid lithium secondary battery.
2. Description of the Related Art
An all-solid lithium secondary battery in which a solid material is used as the electrolyte is naturally safer than conventional lithium secondary batteries in which a combustible liquid electrolyte is used, and can attain high energy density. Therefore, in recent years, research and development of all-solid lithium secondary batteries is being actively conducted.
An all-solid lithium secondary battery includes a positive-electrode active substance layer and a negative-electrode active substance layer, and a solid electrolyte layer interposed between these active substance layers. The positive-electrode active substance layer and the negative-electrode active substance layer both contain an active substance which is capable of occlusion and release of lithium ions. In an all-solid lithium secondary battery, with oxidation/reduction of the positive electrode and the negative electrode, lithium ions migrate in the solid electrolyte layer between the positive-electrode active substance layer and the negative-electrode active substance layer, whereby the lithium secondary battery can be charged or discharged.
For example, International Publication No. 2011/128976 (hereinafter “Patent Document 1”) discloses an all-solid lithium secondary battery in which polycrystalline lithium lanthanum titanate is used as the solid electrolyte.